5-Point features of fixed configuration Switch

In fact, many users are not very familiar with fixed configuration switches, especially their characteristics and performance. However, we can see from the data that their market demand is gradually increasing. Fixed configuration switches generally have fixed port configurations. Although the expansion of fixed configuration switches is not as good as that of chassis switches, the cost is much lower. It is often used as a switch in the access layer of a large network or as a backbone device of a small or medium network. When purchasing a service, you should consider its forwarding performance, port type, and stackable features, as well as whether it supports multi-layer switching, QoS Assurance, multi-route protocol, and manageability.

Port type and features

A fixed configuration switch is generally directly connected to a user device, so it requires a high port density of 10/100 M. If you need a gigabit network connection to the desktop, check whether it supports a large number of Gigabit ports. In addition, switch-level connections also require Gigabit ports; whether automatic MDI/MDIX ethernet cable detection is provided is also worth noting, which facilitates user installation. Some switches can also limit the port data transmission rate to meet certain special requirements; it also depends on whether the switch supports IEEE 802.3ad link bundling and provides aggregated high-speed channels between switches. Port Mirroring is also necessary to facilitate the management of data streams in the network.

Forwarding capability

Because the switch is in the access layer, the switch is usually fully configured. Therefore, you need to check the forwarding performance of the switch engine to see if it can ensure that all ports can forward packets at the same time.

Stack capability

Fixed configuration switches can be stacked to meet the network requirements of a large number of hosts. The connection rate between stack switches directly affects the performance of the entire system. In the past few years, the connection rate between stack switches has increased from 1 to 2 Gbps, and some vendors have now been able to provide 40 Gbps bandwidth. In addition, the user should check whether the switch has a dedicated stack interface, that is, implementing the stack will not reduce the number of gigabit interfaces.

Stack introduces the reliability of devices. Most switches on the market still follow the principle of gigabit interface interconnection although they have dedicated stack modules. When multiple switches are connected into a ring by stacked cables, it looks like a network device, but it is like wearing them together with a gigabit interface. Due to Spanning Tree, one of these stacked cables is blocked by the protocol, seriously affecting forwarding performance. When a switch or cable in the entire stack fails, the Spanning Tree converges again, and the network will be unavailable for at least dozens of seconds.

Some manufacturers use special stacked interconnection cables and stack software to connect multiple individual fixed configuration switches to a unified logical unit. To effectively balance traffic load, data packets are allocated to two logical loop paths. The output queue calculates the path usage to ensure balanced traffic load distribution. The way the system provides services for traffic depends on its service level CoS) or the DSCP value of the differential service code point. Low-latency traffic gets a higher priority. In terms of stacking, if congestion or link failure occurs, the available bandwidth of the stack link will be reduced, and the switch will ensure the transmission of key applications in the stack based on the different priorities of data packets.

User Management and network security policies

It is necessary for a fixed configuration switch to control user access. For example, the 802.1x control protocol supported by the vswitch ensures that only authenticated users can use network resources, and some support binding MAC addresses and ports to restrict unauthorized users from accessing the network. Of course, you can also implement the control function by supporting the access control list.

Service quality

To establish an end-to-end QoS solution in the network, the switch must have excellent support for QoS, so that the network administrator can protect the application systems of key tasks. For example, some fixed configuration switches use WRR schedulers to classify latency priorities for latency-sensitive applications. They also support congestion management and Traffic Shaping, such as WRED, and support stream-based dynamic memory and bandwidth allocation, this dynamic allocation is used together with the User-Defined queue threshold and configurable queue weights to ensure that time-sensitive traffic is properly processed without packet loss. These thresholds and queue weighting can be dynamically adjusted. In addition, it is recommended that vswitches support multi-layer switching, a wide range of routing protocols, and multicast. It should be emphasized that when stack is required, you need to carefully analyze the stack technology of the switch.